Process for the manufacture of artificial silk filaments from nitrocellulose.



percentatge'ot water.

, UNIJFEI) STATES PATENT QFFliQE.

CHARLES BOT'ILER, QF JULIGH, GERMANY, liSSlGNOR TO KUNST'FADENGESELLSOHAFT MIT BESQHRAlXKTER llAF'lUNG, OF JULlUl-l, GERMANY, ACORPORATION.

PROCESS FORTHE MANUFACTURE OF ARTIFICIAL SILK FILATKENTS NITBOCELLULOSE.

Specification of Letters Patent.

Patented Sept. 2d, 19%.

Application filed December 4,1906. Serial N01 346,21

To all whom it may concern:

Be it knownthat I, CHARLES Bowman, a subject of the German Emperor, an da resident of .liilich, Germany, have invented a. certain new and usefulImproved Process for the Manufacture of A rtilicial Silk Filaments lromNitrocellulose, and i do hereby declare the following to be a lull,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame, reference being had to the accompanying drawings, and to lettersof reference marked thereon, which form a part of this specification.

My invention relates to the art of manufacturing socalled artificialsilk or artificial sill: filaments from nitrocellulose is comparativelynew and of late years particularly has been in a state of activedevelopment. An important point or progressive knowledge forming a partof the observations necessary in considering such manufacture consistsin the observation or determination of at what .moisture contents thenitrocellulose which serves as the starting or base material can be mostadvantageously brought into solution with the view of producin therefromas perfect an artificial silk as possible. The investigations made inthis domain have found their expression in a number of Letters Patentand applications for Letters Patent each of which has had [or object toobtain protection for the use in the manufacture under notice ofnitrocellulose containing a dolinite In this connection are concernedthe folloWing:-l. The specification accompanying an application forLetters Patent in Germany made by J. Dongs, of liesancon France, No.B11841, Class 29b, describing the use of nitrocellulose having from 6%to 10% water content. The specification accompanying aniapplication l'orLetters Patent in Germany made by Johann Stoerck, of Brussels, Belgium,No. Stjflllfj, Class 2910, describing the use of nitrocellulose havingfrj0ml2% to 20% water content. 3. The specification oi German LettersPatent granted to llilaire do Chardonnet, of Paris, France, No. 81599,describing the use of nitrocellulose havingfrom 25% to 30 itwiuiorcontcnt. 4.

est and clearest solution possible in the known solvents, as well as inrespect of the further working up of the collodion solution obtained inthis way and of the final product thereby obtained into artificial silk,lies between 20 and 25 per cent.

Departing from the methods described in the specilications hereinbeforementioned, it is found dil advantageous to carry out drying by presses,in a current or air or by heat, as is necessary where the water contentis below 20 9?; It is also found that by a single whirling in acentrifugal machine the water contentef the nitrated cotton coming fromthe washing machines can only be reduced down to awater content 01'about 25% so in carrying out the improved method, while observing therules laid down by practice, the once whirled nitratcd cotton isintroduced in smallportions into a second and thence into a third and ifnecessaryinto a fourth centriiugal machine and in this way, by keepingtime accurately to seconds, a regular abatcnien t of the water coutcntwithin the limits of a few per cent. is successfully obtained. Thenitrated cotton prepared in this careful Way and in contradislinction toprevious experience and observation canin all cases be brought to aneasy and clear solution which filters excellently Well. The solutiontakes place in closed vessels in the proportion of 18 to 23 kilos, dryweight, of nitraicd cotton to lOQ liters of solvent, consisting of amixture of alcohol and ether in the proportions of 352 or 111; this ishowever only an example. Other relative proportions of weight andmeasurement, as well as mixtures of other known solvents such as methylalcohol, acetone etc., may how ever be employed.

The most important advantage however of the collodion solution preparedfrom a nitrocellulose with a water content 01 21 to 24 per cent.consists in addition to the advantages stated in its capability oi beingeasily and regularly spun and its simplified denitrati on in theobtaining of a final product which is characterized by special strengthof filament and increased brilliancy especially in a dyed condition.

What I claim is:-

.l. The herein described process for the manufacture of artificial silkwhich consists in treating nitrocellulose to reduce the water contenttliereoF-to from 21 to 24 per cent.

and addinga solvent therctoto form a collodion solution.

collodlon solution by dissolving said nitrocellulose in a mixartificialsilk which consists in reducing the water cou- 15 ture of alcohol andether or the like.

3. 'llieiierein described process for the manufacture of artificial silkwhich consists in suhjccting nitrocellulose to centrifugal action toreduce the water content thereof, to

" from 2]. to 24 per cent. and in mixing the sznne with :1

tent of nitrocellulose by subjecting the same to successive centrifugalactions for predeterminedintervals of time.

In testimony whereof, I have signed my name to this specification, inthe prcsence of two subscribing witnesses.

CHARLES BOTTLER. Witnesses Bnssin L. Dunning LOUIS VAMnonY.

